So the problem is that you need a definitive answer regarding whether the rate is eligible without asking the person on your side who negotiated the contract or asking your organization for a copy of the contract, right?

Depending on the size of the property and the size of the contract, I'd probably try to start by contacting the hotel's sale manager. I don't think a random front desk agent would know and they might be tempted to just make up an answer (perhaps not even understanding the question or why you care) to make you go away. You certainly want to know the person's name and job title and ideally to get the answer in writing, in an email to you, that references your specific reservation confirmation number.